The construction of brick or block buildings, and glasswalled buildings, is often performed with the use of a wooden, concrete or metal frame as the supporting member, to which the outer wall, or "veneer", of bricks or blocks or panels or glass is linked by ties to prevent it from toppling outwards. It is well recognized by structural engineers experienced in the aseismic design of buildings that brittle non-structural elements such as masonry veneers, precast panels or curtain wall constructions must be separated from the seismic resisting frame so as not to modify the seismic response of a building structure subjected to lateral loads.
Substantial relative dynamic in-plane displacements of the veneer and the frame may occur under seismic attack during an earthquake, or under severe wind loadings, and can result in failure of currently known ties, resulting in severe damage to veneer walls and/or the support structure. Other strains apply in wooden-framed brick or block veneer buildings in the period after construction, when the wooden frame has a tendency to shrink and/or warp slightly as it loses moisture to the atmosphere, and the brick or block veneer expands as moisture from the atmosphere is absorbed.